Before you flash, the first thing you will need to do is H-SPL, the package and instructions can be found here:
http://forum.ppcgeeks.com/showthread.php?t=93252
After you've been Hard-SPL'd, download your favorite ROM. The process for installing the ROM will be EXACTLY like doing the upgrade from 6.1 to 6.5.
If you decide to go with BNR there are certain files which need to be downloaded in order to use certain features (i.e camera, gps, and camcorder are a few i've noticed). I can help make sure you download and install only the files you will need.
Also, watch this video on youtube about flashing:
http://www.youtube.com/watch?v=te7CPM3yeUk
*edit*
BTW, if you want to change your today screen to include the lock option, go to start > settings > today. Click the Items tab at the bottom, there should be an option for lock device. Now on your today screen a lock device icon will be visible...the same can be done for calendar, tasks, voice mail, etc.